Paracoccidioides species present distinct fungal adherence to epithelial lung cells and promote different IL-8 secretion levels

AbstractFungi that belong to the genusParacoccidioides are the etiologic agents of paracoccidioidomycosis, a human systemic mycosis, which occurs in Latin America. Epithelial cell is one of the first cells that interact with these fungi and responds by secreting inflammatory mediators such as cytokines. In the present study, we demonstrate that yeasts of different isolates ofParacoccidioides brasiliensis (Pb18 and Pb03) andParacoccidioides lutzii (Pb01) distinctly promoted interleukin (IL)-8 secretion by the lung epithelial cell line A549. Depending on the isolate, this cytokine release may rely on the epithelial cell interaction with fungal secreted components or direct contact with the pathogen. In addition, adhesion of yeasts to the pulmonary epithelial cells was also different amongParacoccidioides isolates, and the highest percentage of A549 cells with adhered fungi was observed withP. lutzii. AllParacoccidioides isolates induced an expression increase of α3 and α5 integrins in A549 cells and, using small interfering RNA, we observed that the integrin silencing promoted a reduction ofP. lutzii adhesion, which suggests the involvement of integrins in this event. Together, these results indicate that host epithelial cell response may depend on the isolate ofParacoccidioides.
Source: Medical Microbiology and Immunology - Category: Microbiology Source Type: research